Aggregation can profoundly alter the excited-state properties of organic chromophores; however, crystalline supramolecular polymers are often targeted for photocatalytic conversion of solar energy due to favourable charge delocalization or exciton transport. Here we exploit aggregation as a strategy for organic chromophore rigidification to activate photocatalysis by stabilizing localized excited states. Using amphiphilic distyrylanthracene derivatives, we show that aggregation in water enhances the availability of excited states, enabling light-driven transformations of solar energy into storable fuels. We found enhanced reactivity to correlate with increased local excited-state population, underlining the role of self-assembly in restricting intramolecular motion and suppressing unproductive non-radiative decay. We observed photocatalysis to be maximized in kinetically trapped aggregates, outperforming their thermodynamic counterparts, to challenge conventional paradigm that favourable activities require extended assemblies. By achieving excited-state confinement and reactivity instead of charge delocalization, this work reports aggregation-induced photocatalysis as a strategy for preparing photostable, emissive and functional organic photocatalysts in water.

The increasing use of nuclear energy, a reliable baseload power with minimal greenhouse gas emissions, makes managing the heat of dry storage for spent nuclear fuel (SNF) a key engineering issue. Our research indicates that strong heat layers form in standard setups, with over 40% of the vault exceeding 85 °C when airflow stops. A staggered cask setup with outlets on both sides and a 0° inlet yielded the best results, exhibiting the lowest standardized temperature (θave = 0.23) and maintaining wall temperatures below 65 °C. Input speed (4.0–6.0 m/s) is the most significant factor, dropping output temperature from 80 °C to 38 °C. While convection is the primary method of heat transfer (over 90%), radiation becomes significant in low-flow areas, although its effect diminishes as surface temperatures increase. Pressure loss stays low (about 3.2 Pa), which is suitable for mechanics. To improve the system’s practicality and sustainability, it is advised to use both active and passive cooling and to reuse low-grade heat. This work provides reliable guidance for HVAC design under full-load conditions, enhancing the safety, energy efficiency, and cost-effectiveness of SNF storage.

Many industrial sectors are concerned about microbiological contamination and the associated risk of microbiologically influenced corrosion (MIC). This applies in particular to the transmission and storage of fuels in the refining industry. Exceeding a certain level of these contaminants poses a serious risk to fuel quality and can cause storage and pipeline infrastructure corrosion. This situation requires an urgent evaluation of microorganism levels in the fuel to avert such detrimental consequences. Diesel fuels containing biofuel additives are particularly susceptible to these phenomena. Traditional detection methods are limited by low sensitivity, high costs, and long turnaround times, making them unsuitable for quick, on-site, and real-time detection and monitoring. A novel approach involves the application of microwave dielectric testing to quantify microbial load in diesel fuel. Microwave dielectric spectroscopy offers a non-destructive, label-free solution, providing rapid information on microorganism presence. Combined with chemometric techniques, it effectively estimates total microorganism counts in diesel fuel. Measurement in the X-band range (8.2–12.4 GHz) takes a few seconds. Calibration with known bacterial and fungal concentrations (103 to 107 CFU/mL) and principal component analysis (PCA) of the spectroscopic data allow for clear differentiation of contamination levels, categorizing them from acceptable to hazardous. The sensitivity limit of the proposed method corresponds to a bacterial concentration of 103 CFU/mL.

Design and Analysis of Static Composite Fuel Storage Tanks: Alignment with ASME Section X

Groundwater is vital for domestic, agricultural, and industrial use; however, previous studies have indicated that its quality often fails to meet drinking water standards. The sources of groundwater contaminants can be from domestic, industrial, saltwater intrusion, surface waste ponds, pipelines, mine pits, underground storage tanks, waste pits, etc. This research investigates the spatial distribution of Total Petroleum Hydrocarbons (TPH) contamination in groundwater surrounding fuel storage tanks, using the LeGrand method to assess groundwater vulnerability based on five physical environmental parameters. The study employs a quantitative approach, incorporating primary data from well measurements and secondary data from geological and land use maps. The results reveal that shallow groundwater levels significantly increase vulnerability to contamination, while the type of soil and aquifer permeability also play critical roles in contaminant transport dynamics. In the second research location, the analysis focuses on benzene contamination, with low concentrations below 0.02 ppb. Despite the low levels detected, the potential for contamination remains a concern due to the proximity of the gas station to residential areas. Statistical correlation analysis demonstrates a significant inverse relationship between TPH concentrations and vulnerability scores. The study underscores the importance of preventive measures to mitigate contamination risks, involving collaboration among stakeholders.

High-space industrial facilities often store substantial quantities of flammable volatile organic compounds (VOCs), posing significant fire and explosion hazards. This study employed computational fluid dynamics (CFD) to investigate the migration and diffusion characteristics of VOCs in a semi-enclosed, high-space wood chip fuel storage shed. A three-dimensional transient numerical model was developed based on a real-scale industrial prototype, incorporating the Realizable k−ε turbulence model with species transport equations. Validation using experimental data demonstrated good agreement between the model and experimental results, with a maximum relative error of 5.0%. A systematic assessment of key parameters was conducted, including time, ambient temperature, relative humidity, wood chip stack height, and VOCs type. Evaluation metrics comprised the surface-average mass fraction and the proportion of areas exceeding 5% of the lower explosive limit (LEL). The results show that peak concentrations occurred at 25~27 min. The system reaches quasi-steady state after 60 min. At 300~304 K, the lowest peak mass fractions are observed (0.31% and 0.43% at 19 m), yet the area exceeding 5% LEL was the largest. Moderate humidity (40~60%) reduces peaks by 0.06~0.11%. A stacking height of 7.5 m reduces peak values to 0.21% (left) and 0.28% (right), while a 10 m height increases the hazardous area to 48.87%. Low-polarity VOCs (C10H16) spread widely (34.10% exceeding 5% LEL area), whereas polar VOCs (C15H26O) accumulated locally (4.48%). These findings provide theoretical guidance for VOC hazard control and ventilation optimization in high-space biomass fuel storage facilities.

The key to achieving net-zero CO2 emissions by 2050 lies in our ability to convert renewable energy into storable fuels, with hydrogen playing a crucial role in connecting renewable energy sources to end-users. However, the challenge of producing hydrogen cost-effectively and on a large scale is complex. This challenge demands a thorough understanding of electrocatalysis to develop efficient catalysts. Designing stable and effective electrocatalysts for the challenging water electrolysis is difficult, and we still lack a fundamental grasp of the processes that govern catalyst transformation and their ultimate performance and stability. The performance of an electrocatalytic material largely depends on its surface and interfacial characteristics. This highlights the importance of gaining a deep understanding of the surface sites, especially during operation, as both their structure and composition can change and evolve. These changes can create active sites with distinct electronic properties compared to the original bulk phase, even though they remain closely connected. Only by combining operando spectroscopy with electrochemical measurements can we gain a deeper understanding of the various phenomena occurring during the water splitting reaction. Current research in electrocatalysis primarily examines changes on catalyst surfaces. To understand how solid-liquid interfaces influence electrochemical processes, it is crucial to study the surface chemistry at the electrode-electrolyte boundary. In this talk, I will cover examples of changes to surface composition and structure that are dynamically in nature, with direct impact to a material ability to catalyze the water splitting reaction in different media. furthermore, I will demonstrate how the NSRRC beamlines provide essential insights into this area. Our experimental results underscore the importance of in-situ/operando X-ray characterization in revealing the true mechanisms behind catalytic reactions. This allows us to bridge the design principles derived from fundamental studies with the challenges of applying them in real-world systems, where additional constraints must be taken into account.

An analysis of available data on the conditions for the initiation of delayed hydride cracking (DHC) as one of the mechanisms that can cause integrity loss of fuel zirconium cladding under dry storage conditions was performed. Based on the available experimental values for different zirconium alloy grades, a recommendation was made to use 5.0±2,5 MPa·m1/2 as a conservative critical value for the stress intensity factor in the vicinity of a crack, whose exceeding may result in DHC. Stresses arising in the fuel cladding can be caused by mechanical interaction between the fuel pellet and the cladding, pressure created by gaseous fission products (GFPs) under the cladding, and residual stresses in the weld joint zone. In the implementation of the dry storage technology, the maximum reduction in the radial gap between the fuel pellet and the cladding does not exceed 2.2 μm (for E110 cladding at a GFP pressure of 2.85 MPa), which is less than the minimum initial gap typical for irradiated fuel rods (15 μm). Therefore, it was concluded that the formation/growth of stresses in the fuel cladding, which could cause DHC initiation due to mechanical contact between the fuel pellet and the cladding, can be disregarded. Using the VERLIFE methodology, the stress intensity factor (KI) was calculated for the maximum permissible size (depth) of a postulated internal crack in the nuclear power industry, which is 0.25 of its thickness. This size is greater than the maximum fretting wear (10%) of the fuel cladding and is therefore more conservative. The set of calculations enabled to conclude that under thermal impact in the implementation of the dry storage technology, which includes vacuum drying followed by filling the Multi-Purpose Canister (MPC) with helium until a steady state is reached at a temperature of 350 °C, and during long-term storage of spent nuclear fuel (SNF) in the Ventilated Concrete Casks (VCCs) at the Dry Spent Fuel Storage Facility (DSFSF) site under normal conditions, due to the internal pressure under the cladding (GFPs, pellet), DHC will not be initiated, since the maximum calculated KI value for rods with E110 and ZIRLO alloy claddings is 1.81 MPa·m1/2, which is typical for ZIRLO alloy cladding at the vacuum drying stage (436 °C) and does not exceed the conservative critical value KIC = 5.0±2,5 MPa·m1/2.

Semiconductor photocatalysis presents a promising route to convert solar energy into storable fuels and tackle global energy and environmental challenges. However, its efficiency is often hindered by rapid electron-hole recombination. Covalent organic frameworks (COFs)-a class of crystalline, porous organic polymers-offer exceptional potential for photocatalysis owing to their precisely tunable structures and distinctive physicochemical properties, yet their performance remains limited by intrinsic charge recombination. To overcome this limitation, the construction of S-scheme heterojunctions has been proposed as a promising strategy to enhance charge separation while maintaining strong redox capabilities. This review begins by presenting a comprehensive perspective on the development and scientific significance of S-scheme heterojunctions. It then systematically summarizes the design principles and synthetic strategies of COFs, followed by an in-depth discussion of the fabrication methods and principles of COF-based S-scheme heterojunctions. Furthermore, advanced characterization techniques that enable precise elucidation of charge migration pathways within these heterostructures are highlighted. The review also provides a comprehensive overview of recent applications of COF-based S-scheme photocatalysts, including hydrogen evolution, carbon dioxide reduction, environmental remediation, hydrogen peroxide production, and others. Finally, current challenges and future perspectives are discussed to inspire continued innovation in the development of high-performance S-scheme photocatalytic systems.

The key to achieving net-zero CO2 emissions by 2050 lies in our ability to convert renewable energy into storable fuels, with hydrogen playing a crucial role in connecting renewable energy sources to end-users. However, the challenge of producing hydrogen cost-effectively and on a large scale is complex. This challenge demands a thorough understanding of electrocatalysis to develop efficient catalysts. Designing stable and effective electrocatalysts for the challenging water electrolysis is difficult, and we still lack a fundamental grasp of the processes that govern catalyst transformation and their ultimate performance and stability. Only by combining operando spectroscopy with electrochemical measurements can we gain a deeper understanding of the various phenomena occurring during the water splitting reaction. Current research in electrocatalysis primarily examines changes on catalyst surfaces. To understand how solid-liquid interfaces influence electrochemical processes, it is crucial to study the surface chemistry at the electrode-electrolyte boundary. In this presentation, I will demonstrate how the NSRRC beamlines provide essential insights into this area. Our experimental results underscore the importance of in-situ/operando X-ray characterization in revealing the true mechanisms behind catalytic reactions.

This study explores an energy transition strategy that leverages reversible solid oxide cells (rSOC), power-to-gas (PtG) conversion, and CO2 management to enhance the efficiency and sustainability of secondary aluminum production. A comparative analysis between conventional and integrated energy scenarios highlights the benefits of multi-technology integration. The results indicate that the integrated system increases total energy demand by 27% due to additional energy conversion steps, but eliminates natural gas consumption, reducing dependency on fossil fuels. Additionally, net CO2 emissions are reduced more than fivefold, demonstrating the potential of carbon capture and utilization strategies. The seasonal storage of synthetic natural gas (SNG) and biogenic CO2 further enhances system flexibility, allowing excess renewable electricity to be converted into storable fuels for winter use. Despite higher capital expenditures, the operational costs of the integrated system are 11% lower than the conventional approach due to improved energy efficiency and CO2 taxation savings. These findings underscore the importance of process integration, energy storage, and renewable electricity utilization in achieving a low-carbon, resilient aluminum industry and urban heating networks.

Under the situation with decarbonization and introduction of renewable energy, procurement of frequency containment reserve using distributed energy resources (DERs) has become important. We focus on aggregation using DERs installed in hundreds of consumers and propose a method for determining reserve power shared by each consumer to procure the required amount based on the residential electricity demand. © 2025 The Author(s). IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Aviation has become an essential part of the modern world’s ability to grow personal, market and international connections. To enable continued benefits while reducing emissions, future aircraft will need radical redesign and novel, complementary technologies. Hydrogen aircraft are potentially the means to emissions reduction. As part of the European Union’s (EU’s) Clean Aviation Joint Undertaking (CAJU), it is aimed to have hydrogen aircraft entering into service by 2035. To realise this, it would require the certification of these aircraft in a relatively short timeline, which the CONCERTO project aims to help enable. Given the lack of mature experimental designs and pending certification processes, this endeavour is ambitious. To accelerate this, dedicated preparation for the certification through regulatory analysis should be complete, requiring initial options for technologies and aircraft operations to be defined. The technologies and operations were defined, analysed and weighted in CONCERTO, upon which a Generic Concept was made, outlined in this paper, with Level 1 on the Certification Readiness Level Scale. The aircraft systems which are likely to experience the largest changes; Fuel Storage, Fuel Distribution, Propulsion, Auxiliary Power Unit (APU), Heat Exchange (HEX) System and Sensing and Monitoring for Hydrogen (H2), will be outlined in this paper with respect to their components and integration challenges, and the subsequent changes to operations to enable this.

Spent nuclear fuels (SNFs) are expected to be stored in dry storage systems for extended periods, making the preservation of the SNF cladding integrity critical. One of the key concerns is the embrittlement of zirconium alloy cladding at low temperatures due to hydrogen-induced ductile-brittle transition (DBT). This study examines the impact of hydrogen contents, strain rates, and temperature on the fracture toughness and DBT of Zr-2.5Nb specimens. Results show that increasing hydrogen content significantly reduces fracture toughness, with a pronounced DBT occurring between 100°C and 150°C in hydrogen-charged specimens. At room temperature, hydrides, especially circumferential hydrides, are readily fractured, leading to brittle behavior. However, at elevated temperatures (e.g. 300°C), hydrides are not fractured, resulting in ductile behavior. This study identifies that the δ-to-γ and γ-to-δ hydride transformations, driven by entropy changes and the resulting entropy-driven internal stresses, play a crucial role in determining the mechanical behavior of zirconium alloys. The entropy-driven compressive stresses from the δ-to-γ hydride transformation and hydride precipitation cause embrittlement, while the entropy-driven internal tensile stresses from the γ-to-δ hydride transformation and hydride dissolution promote ductility. The findings suggest that the long-term dry storage of the SNF cladding at temperatures below the δ-to-γ transformation temperature increases the risk of embrittlement because of the accumulated entropy-driven compressive stresses. Additionally, this study highlights the influence of strain rates on the DBT, with higher strain rates leading to higher ductile-brittle transition temperatures (DBTTs) because of increased internal tensile stresses, as observed in impact tests. Lower strain rates, such as those in ring compression tests, result in the fracturing of fewer hydrides and lower DBTTs. This study recommends prioritizing higher-strain-rate testing and monitoring hydrogen contents and hydride transformations in the SNF cladding to mitigate embrittlement risks during long-term storage. Low strain rates may be appropriate for evaluating SNF cladding behavior under creep conditions or assessing susceptibility to delayed hydride cracking; they are not suitable for accurately determining embrittlement and the DBT.

Photocatalytic reduction of CO2 to obtain storable fuels is an effective way to fix and utilize greenhouse gas CO2, ultimately achieving a carbon-free energy cycle. The core of this goal lies the development of efficient, sustainable, and economically practical catalysts and light absorbers. Currently, hybrid photocatalytic systems that immobilize molecular catalysts on covalent organic frameworks (COFs) are of intensified interest, as this strategy enables the simultaneous exploitation of the catalytic properties of high-performance molecular catalysts, together with the durability of heterogeneous semiconductors, based on the readily available synthetic tunability of both components. This review focuses on the significant progress and challenges that have been overcome for the photocatalytic CO2 reduction reaction, mediated by COFs hybridized with molecular catalysts, aiming to provide strong guidance for innovative utilization towards sustainable photocatalytic CO2 reduction in the future.

In line with the IMO strategy on the reduction in GHG emissions from ships, many alternative fuels are being studied to phase out fossil fuels. Among these new fuel candidates, ammonia has gained significant attention because of its capability to hugely reduce CO2 emissions. With the introduction of ammonia as a deep-sea vessel fuel, there are growing concerns about ammonia leakage and its influence on crew, ship, and environmental safety. In this study, an innovative formal safety assessment (FSA) framework integrating a hazard and operability study (HAZOP) and Bayesian network was developed to assess the leakage risks of ammonia fuel storage onboard ships. The proposed risk assessment framework was demonstrated by a case study in which refrigerated ammonia was stored in an independent fuel tank underneath the main deck. Three specific risk control options (RCOs) and their combinations were compared based on the cost–benefit analysis. The results indicate that decision-makers may have the option to execute a risk control option from a cost–benefit perspective. This research provides users of onboard ammonia fuel with an approach for assessing storage and usage hazards and estimating and managing their risks.

High-activity resin hoppers from the Spent Fuel Storage Facility are fluidized and immobilized with a specific cement matrix in the Resin Fixation Facility before disposal in suitable engineered modules at the Near Surface Disposal Facility. Potential exposure rates at various locations within the plant were estimated, using standard codes, prior to radio-active operations. The estimation was essential to implement required radiological safety measures and protocols during actual radioactive operations in accordance with the as low as reasonably achievable (ALARA) principle. The dose estimation highlighted possible hot spots and required radiological safety protocols for safe operations. The estimated radiation levels correlated well with measured radiation levels during actual radioactive operations involving fluidization and immobilization of different levels of 137 Cs total activity, namely 14 Ci and 40 Ci, with an accuracy within 80%. This study demonstrated the effectiveness of the radiation field estimation tool and implemented safety measures in ensuring radiological safety for radiological workers following the ALARA principle.

The Coordinated Research Projects (CRPs) of the International Atomic Energy Agency (IAEA) are a powerful tool for engaging multiple countries that operate spent fuel storage facilities to address important safety issues at a deep level of competence and expertise. One of the topics that needs thorough research is the behavior and condition assessment of spent fuel assemblies and fuel rods during long/very long-term storage in spent fuel storage facilities. Naturally, over an extended period, special attention is drawn to degradation mechanisms, aging effects and aging management programs that should be implemented to avoid and mitigate the impact of degradation mechanisms on spent fuel elements. Studying aging effects and predicting the condition of fuel assemblies is relevant under the conditions of limited access and need to introduce indirect monitoring means. At the first stage of the research, the Operating Experience on Degradation (Aging Effects) at the Dry Nuclear Fuel Storage Facilities was analyzed. This article describes the second step in implementing the IAEA CRP “T13019. Performance Assessment of Storage Systems for Extended Durations (PASSED)”, with contribution of the State Scientific and Technical Center for Nuclear and Radiation Safety (SSTC NRS), which conducts research regarding the Monitoring of Spent Fuel Condition over Long-Term Storage. As an example, the Dry Spent Fuel Storage Facility on the Chornobyl NPP site has been selected and studied. The overall objective of the research provided by the SSTC NRS is to strengthen technical knowledge, experience and understanding of the long-term behavior of dry spent fuel storage systems, as well as inspection and monitoring technologies currently in use.

For reaching the European greenhouse gas emission targets, the phase-in of alternative technologies and energy carriers is crucial for all sectors. For the transport sector, synthetic fuels are–next to electromobility–a promising option, especially for long-distance shipping and air transport. Within this context, the import of synthetic fuels from the Middle East and Northern Africa (MENA) region seems attractive due to low costs for renewable electricity in this region and low transport costs of synthetic fuels at the same time. Against this background, this paper analyzes the role of the MENA region in meeting the future synthetic fuel demand in Europe using a cost-optimizing energy supply model. In this model, the production, storage and transport of electricity, hydrogen and synthetic fuels by various technologies in both European and MENA countries in the period up to 2050 are explicitly modeled. Thereby, different scenarios are analyzed to depict regional differences in investment risks: a base scenario that does not take into account regional differences in investments risks and three risk scenarios with different developments of regional investment risks. Sensitivity analyses are also carried out to derive conclusions about the robustness of results. Results show that meeting the future synthetic fuel demand in Europe to a large extent by imports from the MENA region can be an attractive option from an economic point of view. If investment risks are incorporated, however, lower import quotas of synthetic fuels are economically attractive for Europe: the higher generation costs are outweighed by the lower investments risks in Europe to a certain extent. Thereby, investment risks outweigh other factors such as transport distance or renewable electricity generation costs in terms of exporting MENA regions and a synthetic fuel import is especially attractive from MENA countries with low investment risks. Concluding, within this paper, detailed export relations between MENA and EU considering investment risks were modeled for the first time. These model results should be complemented by a more in-depth analysis of the MENA countries, including evaluating opportunities for local value chain development, sustainability concerns (including social factors), and optimal site selection.

This paper presents a probabilistic simulation framework for quantitatively evaluating the contribution of solar cell generators (SCGs) to modern power systems. Unlike conventional generators using storable fuels modeled by simple two states, solar generation is non-storable and inherently uncertain, requiring a more realistic approach. A multi-state probabilistic model is therefore developed—not as a fixed structure, but as a direct reflection of solar resource variability. By integrating the PV output curve with the empirical probability density function (pdf) of solar irradiance, the model captures weather-dependent generation behavior. Case studies on a scaled Jeju Island system verify its effectiveness in evaluating reliability (LOLE, EENS), production cost, and CO₂ emissions, and demonstrate its value for scenario-based planning under increased solar penetration. The proposed framework highlights the transition from deterministic assumptions to probabilistic realism, offering a robust foundation for sustainable and data-driven energy planning.